The reasons for the leakage of high-pressured ammonia pre-heater row tubes and seals were explained, and how to handle and prevent the occurrence of similar accidents was proposed.

分析尿素装置高压氨预热器多次发生列管及封头泄漏的原因，提出如何处理及防止类似事故的发生。

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Below that is a row of four test tubes, marked with a circle, an X, a square and a plus sign.

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